2 tablespoons butter
1 lb sliced leeks
1 large bunch Swiss chard, stems and leaves finely chopped (about 2 lb)
1 large bunch mustard greens, stems and leaves finely chopped (about 2 lb)
1 1/2 teaspoon za'atar
1/2 lb crumbled feta
8-10 sheets of filo (phyllo) dough
1/4 cup melted butter for the dough
freshly ground black pepper
Preheat oven to 350.
In a large skillet, melt the butter and saute the leeks until soft. Meanwhile, steam the greens in a large pot of boiling water until bright green and soft. Drain the leaves and squeeze dry in paper towels (or spin out in a salad spinner and avoid burning your hands). Add the mixture to the leeks. Saute until well combined and all liquid is evaporated. Stir in spices. Allow to cool slightly. Stir in feta.
Line the bottom and sides of a buttered 10-inch springform pan with 4-5 sheets phyllo dough, buttering between each layer. Fill with vegetable, feta mixture. Top with 4-5 4-5 sheets phyllo dough, buttering between each layer, fold the edges over the top of the pan, brush with butter. Bake 40 minutes or until golden brown. Cool on wire rack, unmold. Best served warm or at room temperature; wait at least 10 minutes prior to cutting for best results.